Engines, for example vehicle engines, are being downsized and boosted, which is reducing the available vacuum from the engine. This vacuum has many potential uses, including use by the vehicle brake booster.
One solution to this vacuum shortfall is to install a vacuum pump. Vacuum pumps, however, have a significant cost and weight penalty to the engine, their electric power consumption can require additional alternator capacity, and their inefficiency can hinder fuel economy improvement actions.
Another solution is a Venturi device that generates vacuum by creating an engine air flow path through the Venturi device to generate a suction vacuum. The flow through (i.e., into the motive section of) existing Venturi devices is typically controlled by a valve in series therewith, which entails connections, tubing, assembly steps, etc. This results in a system where the Venturi device is a small part of a large, heavy, and relatively expensive system. There is a need to simplify this system, and to make it more compact, lighter, and affordable.